The zinc and brick condo high-rise at 108 Arch Street—called Old City 108—was developed by Brown Hill, which also did Memphis Flats, the Ayer and the Porterhouse Condo in New York. The apartment above is one of the three-bedroom/three-bath condos; it's 2,517 square feet. The building has a concierge and parking, and is sold as a "boutique doorman building." Originally listed for $1,495,000 in mid-November last year, the price just dropped to $1,395,000. Should you be interested in living here but not in a buying mood, you can rent—for $10,000 a month.
As a contrast, assuming you like the area, you could live close to 108 but at 112 Elfreth's Alley—on the oldest continuously occupied residential street in the country. This pretty little house has 1,480 square feet and two bathrooms. It was built in 1760, which is apparently when most of the photos were taken. This house was originally listed about five months ago at $650,000. Now it's at $629,000. Oh, and it has its own historical webpage.